. >> reporter:economistellenzentnersays it could provide a critical boost to a fragile economy. >> right now business investment spending is accounting for about 7 president clinton to 10% of economic growth. that's not chump change. >> reporter: even conservative economists embraced the idea. >> he should have proposed this right at the very beginning. >> reporter: kevin hassett of the american enterprise institute says the incentives could add as much as 10% to quipped spending, or about $100 billion. for importantly, he says, it could change the national mood. >> i think at some point americans are going to finally step that the worst is behind us and that we're ready to boom again and this is the kind of proposal that could change the psychology and create the positive momentum we need to really get out of this malaise. >> reporter: the white house says the final cost of the incentives would be about $30 billion. the administration is also proposing a permanent extension of the research and development tax credit. katie? >> couric: all right. anthony mason, anthony, thanks so much. let's